/******************************************************************************
 * QwtPolar Widget Library
 * Copyright (C) 2008   Uwe Rathmann
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the Qwt License, Version 1.0
 *****************************************************************************/

#include "qwt_polar_fitter.h"
#include <qpolygon.h>
#include <qpainterpath.h>

class QwtPolarFitter::PrivateData
{
public:
  PrivateData()
    : stepCount(5)
  {
  }

  int stepCount;
};

/*!
   Constructor

   \param stepCount Number of points, that will be inserted between 2 points
   \sa setStepCount()
 */
QwtPolarFitter::QwtPolarFitter(int stepCount)
  : QwtCurveFitter(QwtPolarFitter::Polygon)
{
  m_data = new PrivateData;
  m_data->stepCount = stepCount;
}

//! Destructor
QwtPolarFitter::~QwtPolarFitter()
{
  delete m_data;
}

/*!
   Assign the number of points, that will be inserted between 2 points
   The default value is 5.

   \param stepCount Number of steps

   \sa stepCount()
 */
void QwtPolarFitter::setStepCount(int stepCount)
{
  m_data->stepCount = qMax(stepCount, 0);
}

/*!
   \return Number of points, that will be inserted between 2 points
   \sa setStepCount()
 */
int QwtPolarFitter::stepCount() const
{
  return m_data->stepCount;
}

/*!
   Insert stepCount() number of additional points between 2 elements
   of points.

   \param points Array of points
   \return Array of points including the additional points
 */
QPolygonF QwtPolarFitter::fitCurve(const QPolygonF &points) const
{
  if (m_data->stepCount <= 0 || points.size() <= 1)
    return points;

  QPolygonF fittedPoints;

  int numPoints = points.size() + (points.size() - 1) * m_data->stepCount;

  fittedPoints.resize(numPoints);

  int index = 0;
  fittedPoints[index++] = points[0];
  for (int i = 1; i < points.size(); i++)
  {
    const QPointF &p1 = points[i - 1];
    const QPointF &p2 = points[i];

    const double dx = (p2.x() - p1.x()) / m_data->stepCount;
    const double dy = (p2.y() - p1.y()) / m_data->stepCount;
    for (int j = 1; j <= m_data->stepCount; j++)
    {
      const double x = p1.x() + j * dx;
      const double y = p1.y() + j * dy;

      fittedPoints[index++] = QPointF(x, y);
    }
  }
  fittedPoints.resize(index);

  return fittedPoints;
}

/*!
   \param points Series of data points
   \return Curve path
   \sa fitCurve()
 */
QPainterPath QwtPolarFitter::fitCurvePath(const QPolygonF &points) const
{
  QPainterPath path;
  path.addPolygon(fitCurve(points));
  return path;
}
